By Olivia Lambert
What happened to pilot Amelia Earhart has remained one of the world's greatest mysteries and while a number of conspiracies surround her shock disappearance nobody knows her fate.
After becoming the first woman pilot to fly solo across the Atlantic Ocean, she embarked on a mission to fly 47,000km around the world, but in July 1937 her plane completely vanished and she disappeared without a trace with her navigator Fred Noonan.
Last week an old photo suggested the pair may have been held as Japanese prisoners. But that rumour was debunked.
It's just one of many conspiracy theories surrounding her disappearance 80 years ago.
She was a spy
A 1943 movie Flight for Freedom suggested Earhart and Noonan were spies trying to gather intelligence about the Japanese in the Marshall Islands ahead of WWII.
There was no evidence suggesting that was true, but last week The History Channel made the claim Earhart and Noonan were captured by Japanese military and became their prisoners after their plane crashed near the Marshall Islands, about 1600 kilometres from their destination of Howland Island.
Former FBI official Shawn Henry revealed a photograph that appeared to show Earhart and Noonan alive. He also claimed the US government knew Earhart was being held in custody by the Japanese. The photo showed a person, who appeared to be Earhart, sitting on the pier looking at a Japanese transport ship with what looked like a wrecked aircraft attached to its stern. A nearby man looks similar to Noonan.
However a Japanese military history blogger Kota Yamano shut down the theory because of a timeline flaw.
"The steam ship on the right of the photo is a Japanese navy survey ship 'IJN Koshu'. The ship participated in search missions for Amelia and arrived at Jaluit Atoll (Marshall Islands) in 1937, but the ship also arrived there sometimes since 1935," he wrote.
Yamano then found a book with the original photograph inside and discovered the photo had been taken two years before Earhart and Noonan went missing.
She was a castaway
Evidence emerged last year that suggested Earhart was making contact for days after her plane disappeared. The International Group for Historic Aircraft Recovery (TIGHAR) believes Earhart safely landed her plane after radio signals and voice transmissions were lost.
TIGHAR's Ric Gillespie said on July 2 1937, four months after beginning her trip, she was flying at 375m looking for Howland Island, southwest of Honolulu, but was low on fuel.
It is believed she was not as close to the island as expected so she safely landed on another island, believed to be Nikumaroro, also known as Gardner Island. It is surrounded by a reef and is about 640km southeast of Howland Island.
Gillespie said her plane vanished on July 2, but between the day she went missing and July 6, there were more than 100 radio transmissions from Earhart calling for help.
"People started hearing radio distress calls from the aeroplane and they were verified," Gillespie said.
Six hours after the pair went missing, a weak voice was picked up by credible radio operators who believed it was Earhart.
A housewife in Texas listening on a short-wave radio also heard her pleas. She heard the plane had landed part in water and part on land. Gillespie said she told operators she was injured, but not as badly as navigator Noonan.
He believed that Earhart landed safely with some petrol left in the tank, because she wouldn't have been able to work the radio without the engine running.
Gillespie said TIGHAR had taken a number of trips to where they believe she landed, but haven't had the right equipment to find debris from Earhart's plane.
It is believed the tide washed it out to sea.
The book Amelia Earhart Lives!, written by Joe Klaas in the 1970s, speculated Earhart was still alive and living as Irene Bolam up until she died in the 80s. The book claimed she assumed a new identity for political reasons and to shadow her fame.
Monsignor James Francis Kelley, a friend of Earhart's, told television reporter Dean Magley in 1987 "after all she'd been through she didn't want to be Amelia Earhart anymore".
In 1965 a former United States Air Force major Joe Gervais was introduced to Bolam by
one of Earhart's friends. TIGHAR reports Gervais saw Bolam and believed it had to be Earhart because of their similar physical appearance. Gervais recognised Bolam was wearing a medallion much like one given to Earhart and a red, white and blue ribbon that was also awarded to Earhart in 1932.
In an interview with The Times, Bolam claimed it was a hoax and "utter nonsense".
She crashed her plane
This is one of the more plausible theories. According to the Smithsonian National Air and Space Museum and the US government, Earhart and Noonan crashed while flying over the Pacific Ocean. The pair told a Howland Island coast guard they were running out of fuel and could not find the island.
Dorothy Cochrane, the curator for the Aeronautics Department at the Smithsonian National Air and Space Museum, told CNN: "It's not an exciting theory. It's not the attention grabber".